A Study on Artifacts Arising in Fluorescence Lifetime Imaging of Metallic Nanostructures

• Main Authors: Chen, Shao-Pai, 陳少白
• Other Authors: Chang Shu-Wei
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/shntw3

碩士 === 國立交通大學 === 光電工程研究所 === 105 === The spontaneous emission of an excited molecule can be tailored by its environment. Modifications of spontaneous emission rate using plasmonic structures are widely investigated for applications ranging from the near-field optics and optoelectronics to biomedical imaging. It is possible to track the spontaneous emission rate of a dipole emitter to see how it interacts with the environment and responds to the morphology of surrounding. In this thesis, we model the fluorescence lifetime imaging of gold nanorod dimers by considering a single dipole emitter as a sensitive probe scanning along one dimension above the metallic nanostructure. The fluorescence lifetime is spatially mapped out as an attempt to reconstruct the image of nanostructures. It is found that the lifetime imaging is not always consistent with the real morphology of nanostructure. Artifacts in lifetime imaging arise due to the strong coupling between the dipolar field and resonance structures. The sharpness of nanorod dimers makes spontaneous emission rate of a dipole emitter vary dramatically and plays an essential part in artifacts. The frequency of a dipole emitter can also influence the lifetime and cause artifacts. Here, we investigate the relation between the orientations of dipole emitters and fidelity of images. At last, we will address strategies to distinguish these artifacts from the real morphology and present a theoretical model based on the waveguide geometry to examine possible origins of artifacts.